Large upgrade and diet for our 2019 Off Grid Trailer's Expedition Trailer -
, From Yue Wu, 4 min reading time
After three years, it was time to replace our factory deep-cycle batteries. We'd always considered switching to lithium iron phosphate (LI), but we waited until we actually needed to make the switch. The advantages of LI batteries are too extensive to list. However, the two most important ones are weight savings and battery longevity. The batteries have a life cycle of 4,000 charges! Even after 4,000 charges, the battery should still be at 80% charge.
We chose a Power Queen LiFePO4 100Ah battery (PQ). If you live in a colder climate and want to charge in colder temperatures, There are now self-heating batteries. This battery was purchased directly from Power Queen. Shipping was fast and free!
Power Queen 12.8V 100Ah LiFePO4 battery, Built-in 100A BMS
Isn't she pretty?
Our original Renogy Rover MPPT solar controller, which we installed, is compatible with lithium batteries. We only needed to create a custom charging profile. This is well documented in the Power Queen manual.
Upgrade process:
The upgrade was fairly simple. We're not afraid of electrical work, especially with 12-volt systems. We removed the factory-installed NOCO charger because it wasn't compatible with lithium batteries. We removed the 7-pin charging cable because charging directly from the vehicle doesn't provide the correct voltage for a lithium battery. We used the recommended 20Ah lithium charger from Power Queen instead. We replaced the alligator clips with an XT60 quick-disconnect connector. This allows the charger to be stored in a separate location and used only when needed.
Power Queen 14.6V 20A LiFePO4 battery charger
This charger can charge a fully discharged battery to 100% in 5 hours. We rarely expect the battery to be completely discharged.
The original deep-cycle batteries weighed 62 pounds each. This new PQ LI battery weighs only 24 pounds! Since we don't usually run our refrigerator in the camper, we didn't see the need to install two batteries. If we want, we can run an SAE extension cable from our 4Runner to the trailer to power the refrigerator through this new setup.
Testing the position and charger
It's difficult to make the wiring look good. There are four positive and negative wires that need to be connected directly to the battery. Everything else is located on the BlueSea fuse block. While a better inverter/charger could have been installed, we rarely use our inverter. For us, the benefit would have been negligible.
Everything reassembled. Quick connector for the charger is shown, and there's a cap/cover for when not in use. Yes, our trailer needs a bath!
We can't wait to try it out in practice. A quick three-hour test, running our Truma refrigerator at 40 degrees Celsius, showed a battery discharge of 0.1 percent. We didn't connect an ammeter to get a more accurate number. An off-grid test is required on the weekend. We performed a quick solar charging test with our 100-watt panel. The results were excellent. The battery didn't discharge while the refrigerator was running and even recharged to enter maintenance mode.Again, further testing is needed, but we shouldn't have a problem keeping this battery charged! We also have a 220-watt EcoFlow panel setup if needed.
Conclusion
The cost of the battery was very competitive with a 100Ah AGM battery. The long-term cost is much lower considering that most AGM batteries have a lifespan of around 300-500 charges, depending on the make/model. The greater ability to discharge a LI battery compared to an AGM battery must also be considered. The weight savings is always helpful, and the better discharge profile of a lithium battery is a huge plus. We are in the early stages of planning an off-grid power supply for our cabin. This micro setup will help us assess what we will need. We will likely start with two of these batteries connected in series to create a 24-volt system.
We will edit this article with some updated numbers once we have had a chance to run this facility for a few days.
Affiliate disclaimer from 4xoverlandadventures
Blog posts
-
, From Liu Ling What is the optimal weight of a 12V battery for a boat?
-
, From Liu Ling Best tips for expanding your existing batteryank: release more performance
-
, From Liu Ling How long do motorhome batteries last?
